Container for transportation of temperature sensitive products

ABSTRACT

A heat transfer device for a container defining a cavity (134) therein, the device having a heat transfer solution for cooling the cavity and reservoir-defining element (143) with a channel (148) which is in communication with the cavity (134) and which is disposed substantially in the direction of the flow of air through the cavity. A container (110) for transporting a temperature-sensitive product, the container having a reclosable, insulated housing defining a cavity therein, a product carrying container having a plurality of corners (140) and capable of being disposed within the cavity, and a plurality of the devices as described elsewhere herein, the plurality of devices disposed within the cavity so as to engage the corresponding plurality of corners of the product carrying container.

RELATED CASE

This application is a continuation-in-part of Applicant's copending U.S.Ser. No. 60/007,302, filed Nov. 6, 1995, the contents of which arehereby incorporated, in its entirety, by this reference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The invention relates to containers. In particular, the presentinvention discloses containers suitable for transporting temperaturesensitive products, such as human blood products.

2. Background Art

The conventional means of shipping blood and blood products involves theuse of an insulated box, with the necessary shipping and warning labels,along with some cooling agent. These cooling agents are typically afrozen gel, dry ice, or glistening (wet) ice.

There are, however, several problems with the conventional approach.First, the styrofoam used for insulation does not degrade readily,leading to disposal problems. These problems are so severe that manycountries ban the use of styrofoam, thus severely restrictinginternational shipments of biological materials. Second, the coolingagents also present numerous practical problems in field use.Specifically, gel systems are often too expensive for routine use anddisposal. As for dry ice, the carbon dioxide gas evolved during shipmentis so dangerous to shipping personnel that hazard warnings must beposted and additional fees paid; furthermore, outright bans on dry iceare pending in several areas. Finally, wet ice poses handling problemsin packing, as well as leakage and product soaking problems.

Existing shipping systems also suffer from other serious problems.First, many systems do not employ coolants in the proper temperaturerange. For example, one company ships vaccine packed in dry ice, eventhrough the specification for storage is approximately -15° C. Theresult of this practice is excessive cooling, resulting in damage to thevaccine.

Another problem often observed with conventional systems is failure tomaintain the proper temperature over time, due to inadequate insulationand/or inadequate cooling pack capacity. Again, the end result isproduct damage.

Yet another problem commonly observed with conventional shipping systemsis a strong sensitivity to infrared heat transfer. Specifically, manysystems heat rapidly when left in direct sunlight. Part of thissusceptibility may be due to the standard industry practice of testingshipping containers only in convective, non-radiative heating systems.While this practice is quite appropriate for shaded or otherwiseprotected systems, these results do not apply to the common situation ofshipping containers left in direct sunlight on loading docks, etc.

An additional problem is that many boxes do not tolerate thecondensation that results during conditions of high humidity. Commonfailures include box collapse due to dissolution of starch seals, aswell as excessive swelling of the box walls themselves.

Finally, the vast majority of shipping systems do not provide uniformtemperatures within the container. For example, one system that iscurrently used to transport blood samples for laboratory analysisconsists of a set of frozen gel packs placed on a shelf at the top of astandard RSC (Rigid Shipping Container) cardboard box. Instrumentedtests of this system, however, showed that only the samples immediatelybelow the cooling packs were ever in the specified temperature range of0 to 10° C.; furthermore, these samples were in this range for only 8 ofthe required 24 hour test duration, even at a mild ambient temperatureof 22° C. Conversely, samples at the bottom of the box were never in therequired temperature range, except for approximately 15 minutes afterloading from the storage refrigerator. Less severe, but stillsignificant, uniformity problems were also found for other shippingsystems. Several of these systems showed extreme temperature inversionsof 10° C. or more, typically the result of the placement of coolingmedia only at the top of the shipping system. Again, samples at thebottom of the box never receive adequate cooling. Similarly, the commonproblems of the failure of shipping personnel to obey "This Side Up"instructions also leads to inadequate cooling of some of the load.

The consequence of these observed problems of conventional shippingsystems is damage to the material being transported. For biomedicalmaterials, such as blood, blood products, pharmaceuticals, etc., loss ofthese products due to heat damage is critical because of the intrinsicfinancial value of these items and because of the potential hazards thatthe use of compromised materials presents. Likewise, heat damage tovarious foods also presents both financial and health consequences.Finally, the loss of flowers and other expensive, heat-sensitivematerials presents serious problems to a variety of industries. Becauseall of the above industries currently experience substantial shippinglosses, the commercial opportunity of the present invention is immense.

SUMMARY OF THE INVENTION

The present invention presents a heat transfer device for a containerdefining a cavity therein, comprising a heat transfer solution forcooling the cavity and means for containing the solution, the containingmeans comprising a reservoir-defining element having a channeltherethrough which is in communication with the cavity and which isdisposed on the element substantially in the direction of the flow ofair through the cavity. In a further embodiment, the invention providesa device wherein the solution comprises a eutectic solution which has apreselected melting temperature. In a further embodiment, thereservoir-defining element comprises three substantially equally shapedtriangular members, wherein each member comprises a front face, anopposite rear face, two vertical side walls interconnecting the faces,wherein each side wall has a first end and an opposed second end and thefirst ends of the side walls are joined together at a junction, a rearwall interconnecting the second ends of the side walls, with the frontface, the rear face, the side walls and the rear wall defining thereservoir for each member, and means for forming a trigonally pyramidalshaped void defined by the three front faces of the members, wherein thechannel is formed on each front face of each member in a direction whichis perpendicular to the rear wall and intersects the junction of the twofirst ends of the side walls.

The present invention also provides a device wherein the threetriangular members are arranged with one of the members intermediate theother two members such that a line through each junction of each memberwhich is perpendicular to the rear wall of that member intersects eachof the other lines at a point which is exterior to the members and isthe center of the void and with each of the side walls of theintermediate member being parallel to a juxtaposed side wall of anothermember. In a further embodiment, the rear faces of the members areco-extensive and form a unitary surface and wherein a fold-line isdisposed in the surface between, and parallel to, each of the juxtaposedsidewalls. In another further embodiment, a surface is formed at theintersection of the front face with each of a respective juxtaposed sidewall, each of the surfaces being complementary in shape to each other.In yet a further embodiment, the shape of the surface is a chamfer.

In an alternative embodiment of the invention, the rear faces arecoextensive and further comprising a means for securing the junction,wherein the side walls are disposed such that one member is intermediatethe other two and its side walls are parallel to a side wall of eachadjacent member and the side walls are spaced apart with a fold linedisposed therebetween, and further having a means for joining togetherthe non-intermediate members by folding along the fold-lines. In afurther embodiment, the means for joining comprises a hook meansdisposed on a selected one of the non-intermediate members and ahook-receiving means disposed on the other non-intermediate member.

In addition, the present invention provides the above-described devicefurther comprising separating means for preventing direct contactbetween the reservoir and a corner of the container. In a furtherembodiment, the separating means comprises one or more solution-free,raised protrusions on each of the front faces.

In yet another embodiment, the reservoir comprises a member having anouter surface and an inner surface, wherein the inner surface forms atrigonally pyramidal shaped void comprised of three triangular innerfaces each having a base edge and an apex, and wherein the apexes ofeach of the triangular faces meet and further wherein each of thetriangular faces is substantially bisected by a channel disposed fromthe apex to the base edge.

In an additional embodiment, the present invention provides a containerfor transporting a temperature-sensitive product, comprising areclosable, insulated housing defining a cavity therein, a productcarrying container having a plurality of corners and capable of beingdisposed within the cavity, and a plurality of the devices of theinvention disposed within the cavity so as to engage the correspondingplurality of corners of the product carrying container. In a furtherembodiment, the present invention provides a container wherein thehousing comprises a durable outer layer and an insulating inner layer,wherein the inner layer is comprised of spun rock. In yet anotherembodiment, the container is substantially fluid impermeable. In yetanother further embodiment, the container is coated with an energyreflective material.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of the container of the present invention.

FIG. 2 is a top plan view of one embodiment of the container of thepresent invention.

FIG. 3 is a top plan view of one embodiment of the container of thepresent invention.

FIG. 4A is a top plan view of the cornerpiece used in the presentinvention.

FIG. 4B is a top plan view of an alternate cooling piece used in thepresent invention.

FIG. 5 is a top plan view of one of the corner pieces of the presentinvention in situ.

FIG. 6 is a side profile view of the cornerpiece of the invention.

FIG. 7 shows the method of folding a flattened cornerpiece template intothe cornerpiece of the present invention.

FIG. 8 shows the temperature profile of the inside of the container ofthe present invention over an approximately 35 hour period.

FIG. 9 shows a top plan view of a further embodiment of the cornerpieceof the invention.

FIG. 10 shows a top plan view of a further embodiment of the cornerpieceof the invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

The present invention provides a heat transfer device 140 for acontainer 110 defining a cavity 134 therein, comprising a heat transfersolution (not shown) for cooling the cavity 134; and means 141 forcontaining the solution, the containing means 141 comprising areservoir-defining element 143 having a channel 148 therethrough whichis in communication with the cavity 134 and which is disposed on theelement 143 substantially in the direction of the flow of air throughthe cavity 134. In a further embodiment, the solution comprises aeutectic solution which has a preselected melting temperature.

In yet another embodiment, the present invention provides theabove-described device wherein the reservoir-defining element 143comprises three substantially equally shaped triangular members 142.Each such member 142 comprises a front face 158, an opposite rear face160, two vertical side walls 162 interconnecting the faces 158 and 160,wherein each side wall 162 has a first end 164 and an opposed second end166 and the first ends 164 of the side walls 162 are joined together ata junction 168, a rear wall 170 interconnecting the second ends 166 ofthe side walls 162, with the front face 158, the rear face 160, the sidewalls 162 and the rear wall 170 defining the reservoir 172 for eachmember 142, and means 174 for forming a trigonally pyramidal shaped void176 defined by the three front faces 158 of the members 142, wherein thechannel 148 is formed on each front face 158 of each member 142 in adirection which is perpendicular to the rear wall 170 and intersects thejunction 168 of the two first ends 164 of the side walls 162.

In yet another embodiment, the three triangular members 142 are arrangedwith one of the members 145 intermediate the other two members 142 suchthat a line through each junction of each member which is perpendicularto the rear wall 170 of that member intersects each of the other linesat a point P which is exterior to the members 142 and is the center ofthe void 176 and with each of the side walls 162 of the intermediatemember 145 being parallel to a juxtaposed side wall 162 of anothermember 142. In a still further embodiment, the rear faces 160 of themembers 142 are co-extensive and form a unitary surface 171 and whereina fold-line 133 is disposed in the surface 171 between, and parallel to,each of the juxtaposed sidewalls 162. In yet another embodiment, asurface 150 (or side slope) is formed at the intersection of the frontface 158 with each of a respective juxtaposed side wall 162, each of thesurfaces being 150 complementary in shape to each other. In a furtherembodiment, the shape of the surface 150 is a chamfer.

In an alternate embodiment, the rear faces 160 are coextensive andfurther comprising a means 176 for securing the junction, wherein theside walls 162 are disposed such that one member 145 is intermediate theother two 142 and its side walls 162 are parallel to a side wall 162 ofeach adjacent member 142 and the side walls 162 are spaced apart with afold line 133 disposed therebetween, and further joining together thenon-intermediate members 142 by folding along the fold-lines 133. In astill further embodiment, the means 176 for joining comprises a hookmeans (not shown) disposed on a selected one of the non-intermediatemembers 142 and a hook-receiving means (not shown) disposed on the othernon-intermediate member 142. In a further embodiment (FIG. 9), the meansfor joining comprises a male member 502 and an opposed femaleinterlocking member 504, wherein the male member 502 has a shaft portion503 of a first selected width and a retention portion 505 of a secondselected width which is greater than the first selected width andwherein the female member 504 defines a first slot 508 of a thirdselected width capable of receiving therethrough the portion 505 of themale member 502 having the second selected width and a second slot 510of a fourth selected width, smaller than the third selected width andfurther capable of receiving the shaft portion 503 therein, whereby uponoperation the male and female portions 502 and 504 interconnect toremovably connect the non-intermediate members 142.

In a further embodiment, one or more separating means 400 are providedfor preventing direct contact between the reservoir 172 and a corner 182of the container 180. In yet another embodiment, the separating means400 comprises one or more solution-free, raised protrusions on each ofthe front faces 158.

In another embodiment, the present invention provides theabove-described device 140 wherein the reservoir 172 comprises a memberhaving an outer surface 190 and an inner surface 192, wherein the innersurface 192 forms a trigonally pyramidal shaped void 176 comprised ofthree triangular inner faces each having a base edge 194 and an apex196, and wherein the apexes 196 of each of the triangular faces meet andfurther wherein each of the triangular faces is substantially bisectedby a channel 148 disposed from the apex 196 to the base edge 194.

In yet another embodiment (FIGS. 1-2), the present invention provides acontainer 110 for transporting a temperature-sensitive product,comprising a reclosable, insulated housing defining a cavity 134therein, a product carrying container 180 having a plurality of corners182 and capable of being disposed within the cavity 134, and a pluralityof the devices 140 as set forth herein disposed within the cavity 134 soas to engage the corresponding plurality of corners 182 of the productcarrying container 180.

In a further embodiment, the housing 110 comprises a durable outer layer112 and an insulating inner layer 120, wherein the inner layer 120 iscomprised of spun rock 122.

In yet another embodiment, the container 110 is substantially fluidimpermeable. In an alternate embodiment, the container is coated with anenergy reflective material (not shown).

Generally, the present invention involves the development of a shippingsystem capable of maintaining temperature ranges adequate for theprotection of biological materials or other temperature sensitivematerials. The temperature ranges of primary interest are 0 to 10° C.,for liquid blood transport, -23 to -15° C., for frozen blood producttransport, and 20-24° C. for platelet transport. By shifting the meltingpoint of the cooling packs of the proposed system, the temperature rangeof other products can also be matched, thereby providing an ideal systemfor the shipment of pharmaceuticals, flowers, and temperature-sensitivefoods. In all of these applications, the entire system is designed to beenvironmentally and user friendly, thus avoiding the restrictions onstyrofoam and dry ice that limit conventional packing systems.

The essential concept behind the current invention is that the load issurrounded by a temperature-controlled, circulating air stream. Thissystem is thereby essentially different from the conventional techniquein which no such circulation is provided.

The overall arrangement is shown in FIGS. 1-10 and is described above.These Figures show various views of the system. Starting from theoutside and progressing inward, the first component of the system is theouter box. This box is a conventional B-flute RSC. (The "flute" refersto the size of the convoluted center section of a cardboard box; "B" inparticular designates the standard, approximately 2 mm section thicknesscommonly used for medium-sized boxes.) This box, however, may have ametallized outer section to reduce radiative heat transfer. This boxalso may have an inner wax layer to prevent condensation damage to thewalls, as well as stitched seals to prevent seam failure due tocondensation. When properly taped, the box also provides leakresistance.

The next component is the insulation, consisting of a 2.5 or 5.0 cmlayer of rock wool inside a sheath of metallized film. This combinationhas several advantages over the styrofoam commonly used in insulatedshipping containers. First, rock wool provides a slightly greater Rvalue (the relative resistance to heat transfer) than styrofoam. Second,rock wool, being a by-product of iron ore processing, is environmentallysafer than styrofoam; this wool is actually used as the growth matrixfor hydroponic farming. Third, rock wool is much more flexible thanstyrofoam. Rock wool insulation can therefore be packed at the cornersand joints, thus avoiding the gaps that cause substantial heat loss atthe joints of styrofoam systems.

The next component is the cooling packs (cornerpieces), which are placedat the corners of the inner chamber. A detailed face view of thesepacks/cornerpieces is shown in FIG. 4A and has been described above.These packs consist of three triangular sub-sections. When folded, thesethree sub-sections meet to form a three-faced pyramid, with an open baseto receive the corner of the inner chamber box. Eight of these pyramidsare thus required to match the eight corners of the inner chamber. Eachof the triangular subsections has the illustrated center groove foradded strength and enhanced air flow. Each sub-section also has theillustrated side slopes for high strength molding and easier boxinsertion. The sub-sections are filled with either water or methylcellulose gel for approximately 0° C. transition; the addition ofincreasing amounts of sodium chloride provides successively lowertransition points down to the eutectic limit. The entire assembly isformed from polystyrene or any similar, rigid plastic to ensure lowtemperature strength and the ability of the pack to maintain its shapeafter the cooling medium melts.

The packs are designed to leave air flow channels 131 at the corner whenfolded. These channels 131 thus provide the required heat transferbetween the cooling medium and the circulating air. Saturated air testsof the top packs demonstrate a strong air flow from the lower tip of thepacks. This strong air flow drives the circulation within the system,thus providing quite uniform air circulation.

The placement of the packs on the box corners ensures that the maximumcooling power is applied at the point of maximum heat transfer. Thephysical basis of this arrangement follows from the common observationthat the corners of ice cubes melt before the side walls, due to thegreater surface area per unit volume at the corners versus the walls.The placement of a pack at each corner ensures uniformity throughout thevolume. This uniformity is thus further ensured regardless of theposition of the box, thereby eliminating the problem of incorrecthandling by shipping personnel.

The last component of the system is the internal load container,consisting of an RSC box. Like the outermost shell box, the internalload box is also shielded against condensation damage. The function ofthe internal box is to ensure that the air flow passages remain clear.This box is therefore mounted on the inside of the folded chill packs,as illustrated in FIG. 1. An additional benefit of this arrangement isthat the internal box can be used as a collection vessel in thelaboratory and then stored in a refrigerator until needed, thus avoidingthe problems of carrying and cooling the entire system before shipment.When the load is ready, it can then be transferred to the shippingsystem without the heating that occurs when conventional systems arepacked.

Containers, according to the present invention, have been assembled andtested with a variety of loads and ambient conditions. A representativetest run is shown in FIG. 8. Note that the temperature is reported in °F. rather than ° C. because the domestic box industry and its testingequipment are not metric. The target temperature range is thus 32 to 50°F., which corresponds to 0 to 10° C.

The results presented in FIG. 8 show that the system maintained therequired load temperature for more than 30 hours. The system also showedthe desired tight uniformity of all tested points, versus the largevariations commonly observed for conventional systems. The system alsoreached the desired temperature range quite rapidly, in about 5 minutes,compared to the time spans of up to 2 hours or more commonly observedfor conventional systems.

In addition to the curves, the tests also showed that when systemfailure finally did occur, the chill packs were completely melted. Incontrast, conventional systems typically fail with some coolant stillfrozen. The new technology thus provides more complete utilization ofthe available coolant, thereby extending the useful shipping time. Thisimproved utilization also allows for the use of less coolant for a giventime period, compared to conventional systems. Because less coolantresults in less weight, which is a crucial concern for expressshipments, the new technology thus reduces shipping costs. In the caseof this particular test, 3.5 pounds of coolant provided betterperformance than the 5 pounds of ice required for conventional systems,a significant improvement in both effectiveness and weight.

However, the temperature profiles shown in FIG. 8 indicate one factor toconsider. Specifically, the curves show cooling a lower temperatureregion in the first half hour of operation. Although this drop did notreach the freezing point of blood, this behavior may be unsuitable forcertain applications of the containers. One way of avoiding this problemis to allow the packs to warm to the melting point before utilization.This "equilibration" is essentially similar to the practice of using"glistening" ice for packaging, i.e., the ice is allowed to warm to thepoint of surface melting before utilization. Alternate Embodiment 5describes one such method.

Occasional leaking of coolant at the seams occurs. Although this problemoccurs infrequently, coolant leaks are avoided for most shippingsystems. Therefore, Alternative Embodiment 4 below provides a furthersystem wherein the coolant leak probability is further reduced.

In an alternative embodiment, a ventilated stand-off 400 on the faces ofthe cooling packs is incorporated to reduce the flow of heat from theload directly to the pack. Furthermore, the pure water in the coolingpack is replaced by a gel, again decreasing the heat flow, while alsoreducing the leakage problem. To maintain the same cooling capacity, thedecrease in available thickness due to the addition of the stand-offswill be compensated by increasing the length of the packs.

The stand-offs 400 may also be mounted on the backs of the packs (notshown). This arrangement has two benefits. First, mounting thestand-offs on each side of the packs ensures that the shipping personnelcannot accidentally mount them improperly. Second, the stand-offs on thesides facing the insulation reduce the transfer of heat directly fromthe insulation to the pack, thereby improving the effective life of thesystem.

An additional modification that has also been designed is a cooling pack140', FIG. 4B, to be mounted in the square residual face area shown inthe FIG. 2. This pack 140' consists of four of the triangularsub-sections thereby forming the necessary square face geometry. Theaddition of this pack 140', along with optional 5.0 or even 7.5 cminsulation, is provides the very long shipping time capability neededfor international transport and reduced rate, second day deliveries.

Two additional components can be added to the container of theinvention. These components, consisting of plastic bag liners andabsorbent materials, can improve the ability of the system to containleaks should blood bags or similar containers accidentally break duringshipment. This ability to contain such leaks may be required underinternational shipping rules that are now taking effect in some areas.The addition of these components, however, will not compromise thecirculation patterns of the proposed system and will therefore notadversely affect the performance of the system.

Alternate Embodiment 1

An alternate embodiment of the present invention provides very longstorage times at selected temperatures. In this embodiment, one entirecooling system is placed inside another. For example, the inner systemcould consist of a fully functional 12 inch cube with a 1 inch thickblanket and a 1 inch thick cooling pack, leaving an 8 inch payload box(12 inches minus two sides of insulation or 2 inches, minus thethickness of two packs). This entire system would be placed inside a 16inch cube, again with 1 inch thick insulation and pack thickness,yielding the desired 12 inch payload.

When the existing single system finally fails, which in the case ofliquid blood transport is 10° C., this system is still quite coolcompared to the ambient temperatures which may exceed 70° C. Under thenew approach, however, the inner box would see an ambient only slightlygreater than its target temperature. Since the rate of heat transfer isdirectly proportional to the temperature difference, the innermostpayload is maintained at the target temperature for extensive timeperiods.

This system could be used for the international transport of temperaturesensitive materials, consisting primarily, but not exclusively of,biological samples and compounds, as well as pharmaceuticals.

Alternate Embodiment 2

The cooling packs of the present invention can also be modified forenhanced performance. First, ribs can be added to each section forincreased strength. These ridges are parallel to the central packchannel to provide easier insertion at the box edges. Second, thesections may be extended to include more volume, and thus enhancedcooling capacity. Third, each of the sections may use the previouslydescribed stand-offs 400, which prevent excessive cooling of the payloadat the corner, regardless of the starting temperature of the packs.Fourth, as seen in FIG. 10, the packs also have a snap 402 closuremechanism to hold the frozen units in the proper position. Fifth, thecenter sections of the packs can be severed to improve the flexibilityof the packs. This embodiment could be further enhanced by usingflexible web sections at the periphery to join the three packsub-sections.

Alternate Embodiment 3

The cooling packs of the present invention can be further modified forenhanced performance. As shown in FIG. 9, and further as described inAlternate Embodiment 2, rather than snaps, a male/female locking systemcan be used to hold the units in proper position. The preferability ofusing this locking system stems from the observation that themale/female lock components can be molded into place during fabricationof the units themselves, thereby not requiring additional processing ofthe units during assembly. Upon operation, the male connector "T"portion is disposed through the female connector larger slot and themale connector post is allowed to seat within the female connectorsmaller slot thereby preventing passage of male "T" portion back troughthe larger slot unless the "T" portion is raised in the direction fromthe smaller slot toward the larger slot.

Alternate Embodiment 4

The cooling packs of the present invention can be further enhanced asshown in FIG. 6. The cooling packs may themselves include snapmechanisms 161 or other means for securing the back surface 160 to theremainder of the pack. In such a configuration, flexible coolant packs163 may be placed inside the cavity 165 in the main pack and secured inplace by operation of the snap mechanisms 161. This arrangement providesthe following advantages. First, the inside coolant packs 163 areseparately sealed, thereby reducing the likelihood of extensive leakingin the system. Second, the main coolant pack seals are not subject toflexure when the outer shell is opened or closed, thereby prolonging theuseful life of the main coolant packs. Finally, various inside coolingpacks 163 may be used to obtain different cooling properties withoutrequiring the use of separate main cooling packs 140. Therefore, thesame main cooling packs can be used for cryogenic applications and thenreused for other application, such as platelet transport.

Alternate Embodiment 5

In addition, the cooling packs of the present invention can also beenmodified for enhanced performance for the transport of platelets. Such ause involves the introduction of a special cooling agent for use in thecooling packs and also the use of a set of handling procedures.

The cooling agent for use in transporting platelets consists of achemical mixture and a small amount of sand, higher order olefin (e.g.C-30 or greater) or other inert means for enhancing nucleation. The useof a higher order olefin as the means for enhancing nucleation is thatit has the additional benefit of existing in the liquid state at 37° C.and thus is capable of being pumped into the packs during manufacture atan "elevated" temperature without the need for using separate equipmentto handle the means for enhancing nucleation. The chemical mixture ischosen so as to have a melting point of from 20 to 24° C., preferablyfrom 22 to 23° C., and most preferably about 23° C. In addition, thechemical mixture preferably is of low toxicity and flammability, as wellas low cost. Moreover, it is preferable if the chemical mixture can bedisposed of easily.

One suitable chemical mixture is a combination of alpha olefins. In apreferred embodiment, an approximately 51 wt. % C-18 to 49 wt % C-20 toC-24 olefin mixture is used (C-18, C-20, C-21, C-22, C-23, C-24 and C-30α-olefin, Chevron, Houston, Tex.).

The sand, higher order olefin, or other inert means for nucleating isused to provide a convenient nucleation site in the otherwise smoothcontainer. Such nucleation helps to prevent undesirable supercooling.

The melting point of 23° C. is preferable because of similarsupercooling considerations. Moreover, FDA regulations specify thatplatelets must be maintained at 22±2° C. While melting of phase changesmaterials always occurs at the specified melt temperature, supercoolingcan result in significant, undesirable depressions of the freezingpoint. Using a 23° C. melting point as opposed to 22° C. thereforeprovides further protection against supercooling.

In addition, a novel preparation procedure is preferably employed. Theexact parameters and details of this preparation procedure depend uponthe desired application. For general use, conditions above and below thetarget temperature of 22° C. must be anticipated.

Additionally, an optional pre-conditioning step may be employed. Thisstep involves heating of all packs to 37° C. to eliminate any history ormemory effects, i.e., melting all components at this higher temperatureensures that each use commences with the same, initially liquidconditions. This optional step provides a system where the initialliquid/solid fraction from the previous use is not a concern.

Preparation under these conditions involves the use of common blood bankequipment: a 4° C. refrigerator and a 37° C. "warm" waterbath. For atypical container of eight packs, four packs are placed in therefrigerator (optionally in a waterbath), and four packs are placed inthe warm waterbath. When needed for shipment, the packs are then placedalternatively about the eight corner points of the box, i.e., warmeverywhere next to cold. Because the specific heats are approximatelythe same for solid and liquid forms, and the lower temperaturedifference (23-4=1920 C.) is nearly equivalent to the high temperaturedifference (37-23=14° C.), the warm and cool packs rapidly equilibrate.After equilibrium is reached, about half of the material in the packs isin the liquid phase, and half is in the solid phase. The liquid materialthus protects against cold external temperatures, while the solid phaseprotects against hot external temperatures.

Alternatively, if only very cold external temperatures are expected, allof the packs may preferably be warmed to approximately 24° C.Conversely, if only very hot temperatures are expected, all of the packsshould be conditioned to approximately 20° C.

Finally, the present invention also provides a rapid preparationtechnique, suitable for emergency use. Under this approach, the packsare placed in the same respective hot and cold baths used for generalshipments. Instead of leaving the packs in the baths long enough toreach the bath temperature, however, the packs are removed early.Suitable results can be obtained in as little as 20 minutes. Again,assuming approximately equal temperature differentials, the net systemequilibrates rapidly to the target platelet transportation temperature.

What is claimed is:
 1. A heat transfer device for a container defining acavity therein, comprising:a. a heat transfer solution for cooling thecavity; and b. means for containing the solution, the containing meanscomprising a reservoir-defining element comprising at least threegenerally triangular members, at least one of said generally triangularmembers having a channel therethrough which is in communication with thecavity and which is disposed on the element substantially in thedirection of the flow of air through the cavity.
 2. The device of claim1, wherein the solution comprises a eutectic solution which has apreselected melting temperature.
 3. The device of claim 1, wherein thereservoir-defining element comprises three substantially equally shapedtriangular members, wherein each member comprises:a. a front face; b. anopposite rear face; c. two vertical side walls interconnecting thefaces, wherein each side wall has a first end and an opposed second endand the first ends of the side walls are joined together at a junction;d. a rear wall interconnecting the second ends of the side walls, withthe front face, the rear face, the side walls and the rear wall definingthe reservoir for each member; and e. means for forming a trigonallypyramidal shaped void defined by the three front faces of themembers,wherein the channel is formed on each front face of each memberin a direction which is perpendicular to the rear wall and intersectsthe junction of the two first ends of the side walls.
 4. The device ofclaim 3, wherein the three triangular members are arranged with one ofthe members intermediate the other two members such that a line througheach junction of each member which is perpendicular to the rear wall ofthat member intersects each of the other lines at a point which isexterior to the members and is the center of the void and with each ofthe side walls of the intermediate member being parallel to a juxtaposedside wall of another member.
 5. The device of claim 4, wherein the rearfaces of the members are co-extensive and form a unitary surface andwherein a fold-line is disposed in the surface between, and parallel to,each of the juxtaposed sidewalls.
 6. The device of claim 5, wherein asurface is formed at the intersection of the front face with each of arespective juxtaposed side wall, each of the surfaces beingcomplementary in shape to each other.
 7. The device of claim 6, whereinthe shape of the surface is a chamfer.
 8. The device of claim 4, whereinthe rear faces are coextensive and further comprising a means forsecuring the junction, wherein the side walls are disposed such that onemember is intermediate the other two and its side walls are parallel toa side wall of each adjacent member and the side walls are spaced apartwith a fold line disposed therebetween, and further having a means forjoining together the non-intermediate members by folding along thefold-lines.
 9. The device of claim 8, wherein the means for joiningcomprises a hook means disposed on a selected one of thenon-intermediate members and a hook-receiving means disposed on theother non-intermediate member.
 10. The device of claim 8, wherein themeans for joining comprises a male member and an opposed femaleinterlocking member, wherein the male member has a shaft portion of afirst selected width and a retention portion of a second selected widthwhich is greater than the first selected width and wherein the femalemember defines a first slot of a third selected width capable ofreceiving therethrough the portion of the male member having the secondselected width and a second slot of a fourth selected width, smallerthan the third selected width and further capable of receiving the shaftportion therein, whereby upon operation the male and female portionsinterconnect to removably connect the non-intermediate members.
 11. Thedevice of claim 1, further comprising separating means for preventingdirect contact between the reservoir and a corner of the container. 12.The device of claim 11, wherein the separating means comprises one ormore solution-free, raised protrusions on each of the front faces. 13.The device of claim 1, wherein the reservoir comprises a member havingan outer surface and an inner surface, wherein the inner surface forms atrigonally pyramidal shaped void comprised of three triangular innerfaces each having a base edge and an apex, and wherein the apexes ofeach of the triangular faces meet and further wherein each of thetriangular faces is substantially bisected by a channel disposed fromthe apex to the base edge.
 14. A container for transporting atemperature-sensitive product, comprising:a. a reclosable, insulatedhousing defining a cavity therein; b. a product carrying containerhaving a plurality of corners and capable of being disposed within thecavity; and c. a plurality of the devices of claim 1 disposed within thecavity so as to engage the corresponding plurality of corners of theproduct carrying container.
 15. The container of claim 14, wherein thehousing comprises a durable outer layer and an insulating inner layer,wherein the inner layer is comprised of spun rock.
 16. The container ofclaim 15, wherein the container is substantially fluid impermeable. 17.The container of claim 15, wherein the container is coated with anenergy reflective material.